Tactile control device for a remote sensing device

ABSTRACT

The remote sensing device is added to a fibro-optic illuminating and viewing system such as a colonoscope. The directional sensing device is located in a flexible hood surrounding the distal end of the fiberscope. The sensor devices located in the hood at close spacings consist of semi-conductive digital foam sheath with electrodes located on its inside surface. The sheath and electrodes are attached to an ohmmeter so that when the instrument contacts with the wall, e.g. of a colon, the pressure is measured. The completed circuit forms a signal which is used to direct the distal end of the fiberscope in a direction away from the point of greatest resistance so as to follow the lumen with greater safety. 
     Contacts may also be positioned along the length of the endoscope so as to be activated by tension below the level of pressure required to disrupt the intestinal wall, or when used in other applications, at a level of pressure appropriate to that use.

This is a division of application Ser. No. 182,071 filed Aug. 28, 1980now U.S. Pat. No. 4,366,810.

The invention relates to a tactile control device. More particularly,this invention relates to a tactile control device which is used as aremote sensing device for a fiberscope.

In many cases, it has been desirable to examine internal organs,passages and the like of the human body for purposes of diagnosis,biopsy, and polyp removal in preparation for surgery without cuttingopen the patient. An examination of intestine prior to surgery canenable a surgeon to better prepare for what he encounters at operation.The benefits of a prior visual examination without surgery are obvious.One method of examining the internal organs of the patient without majorsurgery is to insert a remote sensing device such as a fibropticendoscope into the body through a natural body orifice or a speciallyprepared surgical opening.

The use of remote sensing devices for internal examination is notlimited to medicine. Remote sensing devices can be used to examine theinterior of otherwise inaccessible mechanical structures without openingthem; such as aircraft wings, the walls of buildings, the enclosed areasof any structure. In these cases, an internal examination, withoutputting a major opening in the structure, can help to determine thereason for mechanical failure or the level of corrosion levels.

When using a remote sensing device, a common problem arising in medicalor mechanical applications is to be able to maneuver the inspection endof the device around obstructions to the proximity of the area ofinterest. In the past, this maneuvering has been by a trained operatorwho will see the obstruction and then hazard a guess as how to directthe device safely around the obstruction. Such a mode of operationwithout the benefit of binocular depth perception is time consuming.Particularly undesirable in medical observation, is that the prolongedpresence of the remote sensing device in the body and the frequentoccurrence of excessive pressure of contact on an internal organ canresult in damage or perforation at sites most often along the course ofthe instrument in no way related to the visualized area. In more recenttimes, use has been made of fiberscopes which allow viewing aroundbends. These fiberscopes are generally constructed with an elongatedflexible insertion tube having a distal end in which an illuminating andviewing system is mounted and a proximal end in which a control unit ismounted for controlling the bending of the tube at the distal end. Inmany cases, the control unit employs four control cables and two turningknobs to direct the distal end in any one of four directions, i.e., up,down and side-to-side. The illuminating and viewing system usuallyemploys glass fiber optic devices to transmit light to the distal endwhile allowing viewing of the surrounding environment at the distal end.To this end, the control unit is usually connected to a source of lightand carries an eyepiece for viewing purposes.

Generally, when using a fiberscope of the above type, for example forinspection of a colon, the distal end is inserted into a patient via therectum and is then guided through the colon. In order to direct thedistal end and the trailing flexible tube through the colon, the userviews through the eyepiece in the control unit. Should the colon turn,the user manipulates the turning knobs of the control unit to bend thedistal end up, down, left or right so as to follow the bend of thecolon.

However, since the colon follows a tortuous path, the walls of the coloncan fold over so as to define bends of 90° or more. In cases where adistal end of a fiberscope reaches such a bend, a "red out" condition ispresented. That is, the distal end abuts against the colon wall so thatthe user cannot see the direction in which the colon is bent. As aresult, the user must then withdraw the tube inflate further with air orcarbon dioxide and experiment with the turning knobs to determine whichdirection is the correct one to follow. In some cases, aggravatedbendings of the distal end of a fiberscope may tear or otherwise damagethe colon wall. In still other cases, use is made of expensive externalequipment to determine the direction in which the distal end should bedirected.

Accordingly, it is an object of the invention to provide a remotesensing device which can be relatively easily maneuvered aroundobstructions.

It is another object of the invention to provide a remote sensing deviceto ease medical examination of internal organs through natural bodyorifices.

It is another object of the invention to determine that the pressure ofthe instrument against the wall of an organ in no area exceeds thetensile strength of that organ.

It is another object of the invention to provide a remote sensing devicefor internal examination that will automatically provide data to detectobstructions and provide information for avoiding the obstruction.

It is another object of the invention to provide a tactile controldevice which can be incorporated into existing fiberscopes.

Briefly, the invention provides a tactile control device which comprisesa flexible hood, made for example of a flexible digital foam, forcircumferentially surrounding a distal end of a flexible tube of afiberscope and a plurality of pressure-sensitive sensing devices whichare mounted inside the hood for emitting a directional signal inresponse to pressure from flexing of the hood. In addition, a pluralityof contact points can be located along the course of the fiberscopeinside a pressure-sensitive covering to prevent lateral torque of thecolonoscope from causing, for example, a lateral rupture of the wall ofa bowel.

The tactile control device is particularly adapted to function with afiberscope. For example, the tactile control device may be used with afiberscope including an elongated flexible insertion tube, anilluminating and viewing system mounted at a distal end of the tube anda control unit for bending the tube at the distal end in two planes. Inthis case, the flexible directional sending hood is mounted over thedistal end so as to circumferentially surround the illuminating andviewing system. In addition, the hood is disposed to project forwardlyof the distal end so that the sensing devices are disposedcircumferentially forward of the distal end. Upon an inward flexing ofthe hood, the sensing devices are able to emit a signal indicative ofthe location of the flexed section of the hood. These signals, in turn,can be used to activate the control unit of the fiberscope in order todirect the distal end in a direction away from the area of greatestpressure.

The sensing units consist of inside contact points with wires runningalong the instrument inside the pressure sensitive covering, for examplea digital foam layer, to an ohmmeter warning system located proximally.The warning system, in turn, has a resistance measuring device, such asan ohmmeter, connected to the contact points to receive the signal andtranslate the signal into a pressure signal via an ohmmeter measurement.The contact points beneath the flexible hood in the distal portion aredirectionally oriented to provide the operator with information as tothe location of the lumen.

In another embodiment, each sensing device includes a pair ofelectrically conductive plates, such as piezoelectric crystals,microspring sensors or flexible conductive plastic sandwiches which aredisposed in slightly spaced relation to each other and a pair of contactwires. Each wire extends from a respective contact plate so that, whenpressure is applied against the wall of the intestine, the platescontact each other and complete an electrical circuit through the wiresin order to emit a signal.

In an automatic system, a control means is connected to each pair ofwires as well as to the control unit of the fiberscope in order toactivate the control unit in response to a received signal. This controlis so connected with the sensing devices as to activate the control unitof the fiberscope to bend the distal end in a direction away from thesensing device which causes the signal.

In addition, the tactile control device may employ a display board withindicators to indicate the position of a flexed hood section, i.e. thesensing device causing a signal relative to the remainder of the hood.In this case, the indicators on the display board are suitably connectedto the control means or to the pairs of wires leading from the plates inthe hood.

When in use, for example, as in a colonscope, should the distal end ofthe flexible hood of the tactile control device abut against the bend ina colon, a sensing device will close and emit a responsive signal. Theuser may then manually adjust the fiberscope via the control unit so asto move the distal end away from the obstruction. Alternatively, thesignal may be processed automatically by the control means such that thecontrol unit of the fiberscope automatically responds to the signal tomove the distal end away from the obstruction. In this way, the distalend can be maintained in a centered position within the colon passagewayeven if tortuous bends are encountered in the colon passageway. Inessence, the tactile control device augments the illuminating andviewing system of the fiberscope by providing a tactile sense to guidethe colonscope through the colon.

The tactile control device may also have application in industry indirecting wires through conduits; in inspecting parts, for example inairplane wings that require internal inspection; detecting openingswithin walls; and the placement of electrical cables and telephone wireswithin existing structures in which direct visualization is notpossible.

The tactile control device may also be modified to enhance the use of afiberscope. For example, the control device may include a plurality ofpressure-sensitive flexible contacts or switches which can be disposedalong the entire length of a fiberscope. Such pressure sensitivecovering would respond to predetermined contact pressures thereon, forexample the pressures exerted by the wall of the colon. Thus, should thepressure along any portion of the fiberscope exceed the tensilestrength, e.g. of a colon wall, the sensors would give a warning of thisimpending condition.

The pressure sensitive devices which are used both in the tactilecontrol device at the distal end of the fiberscope as well as along thelength of the fiberscope may be of the same type with those at thedistal end being set for greater sensitivity than those along the lengthof the fiberscope.

Further, any suitable type of pressure sensitive device may be usedincluding those with variable conductivity, such as Dynacon A, B, C or Das described in "Computer Magazine", March 1978 issue, under the title"Digital Foam".

These and other objects and advantages of the invention will become moreapparent from the following detailed description taken in conjunctionwith the drawings in which:

FIG. 1 illustrates a schematic view of a tactile control device on thedistal end of a fiberscope in accordance with the invention;

FIG. 2 illustrates a view of the fiberscope of FIG. 1 with the tactilecontrol device removed;

FIG. 3 illustrates a schematic view of a system utilizing a tactilecontrol device according to the invention;

FIG. 4 illustrates a view of the tactile control device at a bend withina colon;

FIG. 5 illustrates a partial cross-sectional view of flexible tube of afiberscope with pressure sensitive switches disposed along the lengththereof;

FIG. 6 illustrates a partial cross-sectional view of a fiberscopeutilizing another form of pressure sensitive switch; and

FIG. 7 illustrates an end view of a modified tactile control device fora fiberscope in accordance with the invention.

Referring to FIG. 1, the directional tactile control device 10 isadapted for mounting on the distal end 11 of a fiberscope 12, forexample a colonoscope. In this regard, the fiberscope can be made of anysuitable construction adapted for entry into other anatomical passagesthan the colon. Such fiberscopes are of known construction and need notbe described in detail.

Alternatively, the fiberscope can be of a construction which can beemployed in industrial applications, such as to inspect lines in anairplane wing.

Referring to FIG. 2, the fiberscope 12 includes an elongated flexibleinsertion tube 13 which terminates at the distal end 11, an illuminatingand viewing system 14 mounted at the distal end 11 and a control unit 15at the proximal end of the tube 13 for bending the tube 13 at the distalend in two planes. For example, the control unit 15 employs two pairs ofcables (not shown) which extend to a bending section 16 of the tube 13as well as two knobs 17, 18 which function to control the cables so asto affect movement of the bending section 16 in one of four directions,namely up, down, and from side-to-side. The illuminating and viewingsystem 14 employs a flexible optic fiber bundle 19 (FIG. 1) whichextends from the distal end 11 to the control unit 15. The control unit15 can be connected to a suitable illuminating means (not shown) whichhas a light source for transmitting light through at least one of theoptic fibers to illuminate an object of interest at the distal end 11 ofthe tube 13. In addition, a viewing means 20 such as an eye-piece or acamera (not shown) is mounted on the control unit 15 to permit viewingof the object of interest via a lens 21 at the distal end 11.

Referring to FIG. 1, the fiberscope 12 has a flexible central shaft 22,e.g. of Teflon which houses the fiber bundle 19 and lens 21. Inaddition, the shaft 22 has a pair of passageways 23, 24 which serve forthe usual purposes, for example for inflating and suction procedures,for biopsy, or other tissue collecting procedures.

The tube 13 of the fiberscope 12 is sized to be passed through a colonand has sufficient flexibility so as to bend during passage through acolon passageway. The flexible tube 13 has a circular cross-section andacts as a conductor of visual and electrical information between theobject under examination and the operator. To this end, the bundle ofoptical fibers 19 transmit light to the distal end 11 in order toilluminate the object under examination, while reflected light is passedthrough the lens 21 to the eye-piece 20 for visual examination.Alternatively, or in addition, a camera can be connected to the eyepiecein order to take still pictures or motion pictures. Also, the imagereceived at the eye-piece may be transmitted to a television monitor orthe like for viewing by others.

Referring to FIG. 1, the tactile control device 10 includes a flexiblehood 25, e.g. of flexible digital foam, such as Dynacon, whichcircumferentially surrounds the illuminating and viewing system 14 atthe distal end 11 of the fiberscope 12. As shown, the hood 25 projectsforwardly of the distal end 11, for example a distance of onecentimeter, and is made in the shape of a ball of flexible material,such as a clear flexible ethlion. In addition, the tactile controldevice 10 includes a plurality of sensing devices 26 which are disposedcircumferentially on the hood 25 forward of the distal end 11 to coverthe inside surface of the hood 25. Each sensing device 26 is responsiveto an inward flexing of a section of the hood 25 in order to emit asignal indicative of the location of the flexed hood section. To thisend, each sensing device 26 includes a pair of electrically conductiveplates 27 which are disposed in slightly spaced relation to each other,for example, at a distance of three millimeters, and a pair of contactwires 28 which are connected to the plates 27. These contact wires 28extend from the plates 27 to a suitable control means 29 (FIG. 3). Asshown, the contact plates 27 are of elongated construction and areformed, for example of piezoelectric crystals or microspring sensors.The spacing apart of the plates 27 and the flexibility of the hood 25are such that the plates 27 of a sensing means 26 contact each otherupon inward flexing of the hood 25 when the hood abuts against the wallof a colon (FIG. 4).

Generally, the contact plates 27 are disposed along the outer edges ofthe hood 25 since this edge generally forms the impact points for theend of the fiberscope 12.

Referring to FIG. 3, the control means 29 is suitably connected to thecontrol unit 15, and particularly to the control knob 17, 18 to actuatethe control unit 15 in response to a received signal from the tactilecontrol device 10 in order to direct the distal end 11 of the fiberscope12 in a direction opposite to the flexed hood section. The control meanshas a second circuit as well as a motorized component in this circuitfor actuating the control knobs 17, 18.

The contact wires 28 and the control means 29 may also be connected to adisplay board 30 having indicators 21 such as lights to indicate theposition of a flexed hood section relative to the remainder of the hood25. Thus, the operator may bend the distal end 11 of the fiberscope 12in accordance with the information received from the display board 30 orthe distal end 11 may be automatically bent via the control means 29.

Referring to FIG. 4, the control wires 28 of the tactile control devicemay extend along the outside of the central flexible shaft 22 of thefiberscope 12 and be covered over by a sheath 36 which usually surroundsthe tube 13 of the fiberscope. Such a protective sheath 36 is sufficientto protect the fiberscope 12 from the fluids and the like found in thecolon. The sheath 36 should also be made of a material which is suitablefor use in the colon.

Referring to FIG. 4, when in use, the fiberscope 12 is inserted into thecolon 33 and travels along the passageway 34 formed by the colon 33.During this time, the operator can view the interior of the colon 33 viathe viewing and illuminating system 14 (FIG. 1). Should a section of thehood 25 contact the wall of the colon 33, the contact pressure flexesthe hood section inwardly. This, in turn, causes the contact plates 27thereat to come into contact and complete the circuit along theassociated wires 28. A suitable signal is then emitted to the controlboard 30 to indicate the area of pressure. This is represented by theappropriate panel indicator 31. Thus, the direction of the pressurepoint of maximum impact on an obstruction is indicated. In addition, thesignal also activates the control means 29 such that the motorizedcomponent of the control means 29 is activated to turn the appropriateknob or knobs 17, 18 of the control unit 15 in the direction required tomove the distal end 11 and thus, the hood 25, away from the point ofpressure.

With the tactile control device 10 in operation, the fiberscope 12 willautomatically seek the most central position within the colon 33 orwithin the lumen of an intestine or any other tedious structure. Thisfacilitates passage and prevents impedance of the fiberscope.

It is to be noted that visual inspection of an internal organ occursthrough the optic fiber bundle 19 in known manner. For example, a lightsource (not shown) projects light via a suitable means in the controlunit 15 into and through some of the optic fibers to illuminate theobject of interest. The lens 21 at the distal end 11 collects thereflected light from the object and transmits the reflected imagethrough the remaining optic fibers to the eye-piece 20 or a viewingscreen for visual examination by an operator.

Referring to FIG. 4, the tactile control device 10 may also include aplurality of pressure-sensitive contacts 35 which are disposed along theinsertion tube 13 beneath a layer or sheath 36 of Dynacon or othersuitable material with variable conductivity. These contacts 35 beneaththe outer sheath 36 form a network of sensors which are able to emitwarning signals when a given pressure is exceeded; thus warning theoperator of impending disruption of the bowel by any portion of theinstrument. As indicated, the contacts 35 may be disposed under thesheath 36 to generate signals to indicate that the sheath 36 is incontact with a bend in the colon passageway 34 with sufficient pressurethat the tensile strength of the colon wall is in danger of beingexceeded. Thus, excess pressure registered e.g. by an ohmmeter fromcontact 35 will signal the operator to cease the application of pressureto the colonoscope until the tube 13 can be reoriented to reduce thepressure against the colon wall. In this regard, the generated signalcan be emitted via a suitable electrical circuit to the control board 30to sound an audible warning signal and/or to give a visual warningsignal.

Referring to FIG. 5, instead of using a flexible sheath with multiplecontacts as the pressure sensitive devices, a series ofpressure-sensitive microswitches 37 can be spaced along the tube 13 of afiberscope under the flexible outer sheath 32. As shown, eachmicroswitch 37 is of a suitable known construction, e.g. employing amovable button 38 which can be depressed into a housing 39 to close theswitch and complete a circuit. For this purpose, a flexible plate 40 ispositioned above each microswitch 37 to close the circuit should thetube 13 be subjected to undue pressure at the location. Each microswitch37 is also connected to a positive wire 41 to emit a signal to thecontrol board (not shown) as above, to inform the operator of an excesspressure condition at the location of the activated microswitch.

It is noted that the microswitches 37 are mounted not only along thetube 13 but also circumferentially about the tube 13. Further, theplates 40 are arranged to press radially inwardly relative to the tubeaxis.

Referring to FIG. 6, the pressure sensitive devices may also be in theform of micro dip switches 42 disposed at intervals along the tube 13.

Referring to FIG. 7, wherein like reference characters indicate likeparts as above, the sensing devices 26 may also be in the form ofmicroswitches as in FIGS. 5 and 6 rather than in the form illustrated inFIG. 1. Further, when used with pressure sensitive devices along thelength of the tube of a fiberscope, the microswitches at the distal endare more sensitive than the sets of proximal switches. Thus, the distalmicroswitches are used for sensitive tip control while the otherswitches are used to prevent disruption of a structure, such as a colon.

This invention thus provides a tactile control device which can beeasily incorporated into existing fiberscopes, particularlycolonoscopes. In essence, the invention provides a remote sensing devicewhich can be used to sense obstructions and to indicate such. Anoperator can the note the obstruction and visually adjust the fiberscopeto avoid the obstruction or the control device may be interconnectedwith a system which automatically corrects the position of the distalend of a fiberscope to avoid a sensed obstruction and maneuvers theinstrument to the center of a lumen by seeking the point of leastresistance. Still further, the invention provides a tactile controldevice which can be used industrially to visually inspect objects whichare relatively inaccessible.

What is claimed is:
 1. In combination with a fiberscope including anelongated flexible insertion tube, an illuminating and viewing systemmounted at a distal end of said tube and a control unit for bending saidtube at said distal end in two planes;a tactile control device includinga flexible hood circumferentially surrounding said illuminating andviewing system at said distal end, said hood projecting forwardly ofsaid distal end; and a plurality of sensing devices disposedcircumferentially on said hood forward of said distal end, said sensingdevices being responsive to an inward flexing of said hood to emit asignal indicative of the location of a flexed section of said hood. 2.The combination as set forth in claim 1 wherein each sensing deviceincludes a pair of electrically conductive plates disposed in slightlyspaced relation to each other and a pair of contact wires, each saidwire extending from a respective one of said plates whereby upon flexingof a section of said hood, said plates therein contact with each otherto complete an electrical circuit through said wires and emit saidsignal.
 3. The combination as set forth in claim 2 which furthercomprises a control means connected to each said pair of wires and tosaid control unit of said fiberscope to activate said control unit inresponse to a received signal to direct said distal end in a directionopposite said flexed hood section.
 4. The combination as set forth inclaim 2 wherein said sensing devices include contact points inside apressure-sensitive digital foam sheath and which further comprises anohmmetric resistance measuring device connected to said contact pointsfor converting said signal into an indication of pressure.
 5. Thecombination as set forth in claim 2 wherein said plates arepiezoelectric crystals.
 6. The combination as set forth in claim 2wherein said plates are microspring sensors.
 7. The combination as setforth in claim 2 which further comprises a display board havingindicators thereon to indicate the position of a flexed hood sectionrelative to the remainder of said hood.
 8. In combination with afiberscope including a distal end, a flexible optic fiber meansextending to said distal end to transmit light thereto, a lens at saiddistal end, an eyepiece at a proximal end to view an image through saidlens, and a control unit for remotely bending said distal end;a tactilecontrol means comprising a flexible hood surrounding said distal end andprojecting forwardly of said distal end, a plurality of sensing devicesin said hood forward of said distal end to signal when a section of saidflexible hood flexes upon contact with an obstruction.
 9. Thecombination as set forth in claim 8 which further comprises a positiondisplay means to receive said signals from said sensing devices and todisplay signals in response thereto to an operator.
 10. The combinationas set forth in claim 8 wherein said sensing devices are contacts insidea pressure sensitive digital foam sheath.
 11. The combination as setforth in claim 8 wherein said sensing devices are piezoelectriccrystals.
 12. The combination as set forth in claim 8 wherein saidsensing devices are microspring sensors.
 13. A tactile control devicecomprisinga flexible spherical hood for mounting on a distal end of aflexible tube, and a plurality of pressure-sensitive sensing devicesmounted in said hood, each said sensing device being responsive to aninward flexing of said hood for emitting a signal indicative of thelocation of a flexed section of said hood.
 14. A tactile control deviceas set forth in claim 13 wherein said hood is a ball and said sensingdevices are disposed circumferentially on said ball without fibropticvisualization.
 15. A combination as set forth in claim 14 wherein saidsensing devices are recessed within said ball.
 16. In combination with afiberscope including an elongated flexible insertion tube, anilluminating and viewing system mounted at a distal end of said tube anda control unit for bending said tube at said distal end in two planes;atactile control device including a flexible hood about said distal end,and a plurality of pressure-sensitive sensing devices disposedcircumferentially on said hood, each said device being responsive toflexing of said hood to emit a signal indicative of the location of aflexed section of said hood.
 17. The combination as set forth in claim16 wherein said tactile control device further includes a plurality ofpressure-sensitive devices disposed along said insertion tube foremitting a signal in response to predetermined contact pressures on saidtube at the locations of said devices.
 18. The combination as set forthin claim 17 wherein said pressure-sensitive devices are flexible tubes.19. The combination as set forth in claim 17 wherein saidpressure-sensitive devices are microswitches.
 20. The combination as setforth in claim 17 wherein said pressure-sensitive devices include aplurality of contacts within an outer sheath of flexible pressuredigital foam and which further comprises an ohmmeter connected to saidcontacts to reflect changes in pressure by variations in electricalconductivity.